A large randomized trial investigated whether vitamin D3 supplementation can improve the course of COVID-19. The study included 1,747 people who had recently been diagnosed with COVID-19 and their household contacts. Participants were given either high doses of vitamin D3 for one month or a placebo.
The results showed that vitamin D did not reduce how often patients needed healthcare, such as hospital visits, emergency room visits or doctor visits. It also did not reduce the severity of symptoms, and it did not affect the risk of family members in the same household becoming infected.
However, the researchers saw a slight trend towards fewer persistent symptoms after two months in those who received vitamin D. Around 21% in the vitamin D group reported long-term symptoms compared to 25% in the placebo group. However, the difference was small and not statistically significant.
The researchers therefore believe that vitamin D is unlikely to reduce acute illness or the need for care in COVID-19, but that it may be worth studying further whether vitamin D can affect the risk of long-term symptoms after infection. No safety concerns with the treatment were reported.
Credit: Patrik Andersson